Yarn tensioning regulating apparatus for stocking machine



5, 1963 RENPEI ABE ETAL 3,408,332

YARN TENSION REGULATING AP ARATUS FOR STOCKING MACHINE Filed Sept. 8, 1965 2 Sheets-Sheet 1 5, 1958 RENPEI ABE ETAL I 3,408,832

YARN TENSION REGULATING APPARATUS FOR STOCKING MACHINE Filed Sept. 8, 1965 2 Sheets-Sheet 3,408,832 YARN TENSIONING REGULATING APPARATUS FOR STOCKING MACHINE Renpei Abe and Kakuji Maruyama, Nishikanbara-gun,

Nigata-ken, Japan, assignors to Nagataseiki Kabushikigaisha, Tokyo, Japan Filed Sept. 8, 1965, Ser. No. 485,722 Claims priority, application Japan, May 19, 1965, 40/ 29,045 1 Claim. (Cl. 66146) ABSTRACT OF THE DISCLOSURE A yarn tensioning device, comprised of a rotatable disc having a pair of upstanding pegs thereon, adapted to vary the tension in a yarn passing over said pegs upon rotation of the disc. The disc is rotated in opposite direction by a pair of solenoid operated cables and the solenoids are controlled by means of a yarn tension detector. The yarn tension detector is comprised of a rotatable member having a yarn guide and light shutter mounted thereon whereby the light shutter is adapted to control the light to a pair of photocells, each of which controls a respective solenoid.

This invention relates to a yarn tension regulating apparatus for stocking machine, and more specifically to a yarn tension regulating apparatus which is capable of detecting changes in yarn tension photoelectrically and of regulating the tension automatically.

In knitting fine-gauge stockings for women, usually the yarn fed from a bobbin is not maintained in a contension on the frame so that the products have different lengths. This has long been a problem for the hosiery industry.

The present invention offers a solution to the problem. In case of hosiery goods, particularly of fine-gauge stockings, unevenness of yarn tension often has a direct bearing upon the length of hose knitted. Since knitting yarns usually employed for such stockings are very fine, they should be strained only to a slight degree. In a yarn tension regulating apparatus, therefore, the tension detecting unit is required to follow positively a slightest change in yarn tension and to instruct the regulator means for action, by transmitting what it has sensed to the latter, so that the yarn can be kept under a predetermined tension.

Generally the transmission of instructions from the detecting unit to regulator means is effected either mechanically or electrically. The latter is more effective in permitting the regulator means to give a sufficient tension to the yarn in response to a slightest change detected in yarn tension.

According to the present invention, a yarn tension detector accommodating a photoelectric means is provided in the detecting unit, so that very small changes in the tension of yarn passing through the unit can be detected by suitable photoelectric elements. Thus, the photoelectric means converts the changes in intensity of light first into electrical changes and transmits corresponding electrical instructions to an electromagnet, which in turn converts the changes into mechanical motions and gives corresponding instructions to a yarn tension regulator in order that the latter can always give a predetermined tension to the yarn. With such arrangements the apparatus of the invention can regulate the tension of yarn for fine-gauge stockings precisely within close tolerances.

To understand the principles of the invention reference is made to the following description of a typical embodiatent O ment of the invention as illustrated in the accompanying drawings, in which:

FIGURE 1 is a schematic view illustrating arrangements of an apparatus which incorporates the invention;

FIGURE 2 is a perspective view of a ya-rn tension detector of the apparatus;

FIGURE 3 is a front elevational view of the yarn tension detector;

FIGURE 4 is a side view of the yarn tension detector;

FIGURE 5 is a front elevational view of a yarn tension regulator of the apparatus; and FIGURE 6 is a side view of the yarn tension regulator.

Referring first to FIGURE 1, a yarn 13 being fed from a bobbin 10 to knitting needles '12 is led from the bobbin 10 to a yarn tension regulator 14, and then through a yarn tension detector 15, and is finally supplied to the knitting needles 12, by way of a yarn guide 16 and eyelet 17.

If any change occurs in the tension of yarn between the detector 15 and needles 12, the detector 15 senses the change and gives a corresponding signal through its photoelectric element to a relay 18, which in turn gives an electrical signal for actuating either of electromagnets 19 and 20. The motion of the magnet 19 or 20 is transmitted through either of releases 49 and 50 to the regulator 14 thereby to effect regulation of the yarn tension accordingly.

Further description will be made hereunder in detail as to the essential component parts.

The yarn tension regulator 15 having suitable photoelectric elements 35A and 35B consists of a cylindrical case 22, a yarn guide 24 swingably protruding from'an opening 23 formed in a suitable area in the side of the case, and a pair of yarn guides 25 and 26 disposed at suitable points sandwiching said swingable guide 24 therebetween.

With suitable supports 27 and 28, the yarn guides 25 and 26, respectively, are fixed in a suitable manner to the side of case 22. The yarn 13 is led through the guides 24, 25 and 26. While the guides 25 and 26 are fixed, the guide 24 can swingably follow any change of yarn tension as it is fitted on one end of arm 29, the other end of which is integral with a shaft 30. The shaft 30 is supported by bosses inside the case 22. To one end of the shaft 30, one end of a weak spring 31 is fitted. The other end of the spring is fitted to one end of case 22, so that the arm 29 is urged in the counterclockwise direction with a slight force. On the left end of case 22 (as seen in FIGURE 4), at least two or more holes 32 are provided at suitable intervals, and a plurality of pipes 33 accommodated in the case 22 are fitted in positions concentric with the plurality of holes 32, as illustrated. On the right end of case 22, projector lamps 34 are provided insertedly in positions concentric with the pipes 33. On the left end of case 22, a holder 36 is fitted for holding photoelectric elements 35 in positions opposite to said lamps 34. The holder 36 has a plurality of built-in photoelectric elements 35 which are concentric with the holes 32, and is also provided with holes 37 concentrically with said holes 32.

Accordingly, if there is no obstacle between the photoelectric elements 35 and projector lamps 34, the elements can receive the rays of light projected by said lamps. At the left end of shaft 30, a screen plate 38 is fitted. If the arm 29 swings in response to a change in yarn tension, the screen plate 38 also swings thereby screening the photoelectric elements 35 against the rays of light from the projector lamps 34, or permitting the elements 35 to receive the light. The photoelectric elements 35 are so designed as to give off a signal if rays of light incident thereon are interrupted. Hence if the screen plate 38 screens either one of the photoelectric elements, as for example at 35A, against the rays of light incident thereon, said element 35A will give a signal. Likewise, if the screen plate 38 interrupts the light path to the other photoelectric element 35B, the latter will give a signal. If necessary, the photoelectric elements may be provided in a larger number than two, i.e., 35A and 3513. The screen plate is equipped with a pointer on the other end, enabling the screening motion to be read out .from the graduations on the end of case 22.

The yarn 39 passes through a yarn guide 40, and passes along the left circumferential side of a yarn tension regulating roll 41 which runs counterclockwise and then along the right circumferential side of another yarn tension regulating roll 42 which runs clockwise, and finally passes through a lower guide 40. Regulating rolls 41 and 42 are supported by holders 43 and 44, respectively, which are spaced a suitable distance from each other and mounted on a common metal base 45. The metal base 45 is provided with a shaft 46 in the center, which is fitted in a hole provided on a housing 47. The shaft end protruding beyond the housing is integrally fitted into an arm 48. The housing 46 is provided with holes on both sides, one each, through which releases 49 and 50 are connected to the tip of arm 48.

It therefore the release 49 pulls, the regulating base is moved clockwise by the arm 48, and the regulating means 41 and 42 are also shifted in positions thereby to lessen the yarn tension. Conversely if the release 50 pulls, the regulating means 41 and 42 are shifted counterclockwise to increase the tension. The base 45 is knurled on the circumference, and a springSl is kept at one end in contactwith the knurled circumference with a suitable pressure. The other end of spring 51 is fitted to the housing. If the photoelectric element 35A gives a signal in response to a change in yarn tension, the electromagnet 20 is thereby actuated through the medium of relay 18, and causes the release 49 to pull as shown in FIGURE 5 so that the regulating means 41 and 42 are turned clockwise to lessen the tension on yarn. On the contrary, if the photoelectric element 35B gives a signal, the release 50 is urged to pull by means of the relay 18 and electromagnet 19, thereby to increase the yarn tension. Yarn can be kept under a suitable tension by selecting an adequate range of swinging motion for the regulating means 41 and 42.

As above described, the apparatus of the invention detects a change in yarn tension With an oscillating yarn guide which is disposed between a pair of yarn guides and is swung by the force of a weak hair spring in one direction, actuates a given photoelectric element in response to the swing of said oscillating intermediate yarn guide, and operates the tension regulating means in ac- "cordance with the photoelectric output of said element,

thereby to maintain a constant tension on the yarn. Thus,

4 the response time required for making a regulatingaction after detection of a tension change is so short and the response is so precise that the knitting yarn can be kept exactly under a predetermined tension. Consequently, not only nonuniformity in lengths of end products but unevenness and other irregularities of stitch and mesh are completely eliminated. With these and other practical advantages, the invention permits stockings of very great commercial values to be manufactured at high yields.

What is claimed is:

1. A yarn tension regulating apparatus for a knitting machine comprising a yarn tension regulator having adjustable tortuous guide means, a pair of electromagnetic means for adjusting said guide means in opposite directions to regulate said yarn tension, yarn tension detector means comprising rotatable lever means having a yarn guide at one extremity thereof and a light shield at the other extremity, a pair of photocell means mounted adjacent said shield, light source means mounted on the opposite side of said shield in alignment with said photocell means, each of said photocell means controlling one of said electromagnetic means whereby upon an increase in tension said yarn guide will cause said shield to block the light to one of said photocells to cause operation of one of said electromagnetic means and upon decrease in tension said yarn guide will block the light to the other of said photocells causing operation of the other of said electromagnetic means.

References Cited UNITED STATES PATENTS 2,745,609 5/1956 Lermont 66146 XR 2,771,635 11/1956 Munch 242154 XR 2,833,491 5/1958 Carroll 242-454 2,949,757 8/1960 Page 66-l46 3,071,163 1/1963 Christiansen et al.

242-139 XR 3,184,820 5/1965 K-anbar 66-132 XR 3,295,788 1/1967 Richter 242-154 3,300,161 1/1967 Hermanns 242154 FOREIGN PATENTS 569,717 1/1959 Canada. 1,087,314 8/1960 Germany.

576,001 3/ 1946 Great Britain. 1,222,209 6/1960 France. 1,319,433 1/ 1963 France. 1,377,602 9/1964 France.

582,349 9/1958 Italy.

MERVIN STEIN, Primary Examiner.

RONALD FELDBAUM, Assistant Examiner. 

